[Python-checkins] python/dist/src/Lib/test test_itertools.py, 1.15, 1.15.6.1

[rhettinger at users.sourceforge.net]

Update of /cvsroot/python/python/dist/src/Lib/test
In directory sc8-pr-cvs1:/tmp/cvs-serv796/Lib/test

Modified Files:
      Tag: release23-maint
	test_itertools.py 
Log Message:
SF bug #793826:  using itertools.izip to mutate tuples

Avoid Armin Rigo's dastardly exercise in re-entrancy.



Index: test_itertools.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/test/test_itertools.py,v
retrieving revision 1.15
retrieving revision 1.15.6.1
diff -C2 -d -r1.15 -r1.15.6.1
*** test_itertools.py	29 Jun 2003 20:36:23 -0000	1.15
--- test_itertools.py	29 Aug 2003 23:13:16 -0000	1.15.6.1
***************
*** 426,429 ****
--- 426,459 ----
              self.assertRaises(ZeroDivisionError, list, dropwhile(isOdd, E(s)))
  
+ class RegressionTests(unittest.TestCase):
+ 
+     def test_sf_793826(self):
+         # Fix Armin Rigo's successful efforts to wreak havoc
+ 
+         def mutatingtuple(tuple1, f, tuple2):
+             # this builds a tuple t which is a copy of tuple1,
+             # then calls f(t), then mutates t to be equal to tuple2
+             # (needs len(tuple1) == len(tuple2)).
+             def g(value, first=[1]):
+                 if first:
+                     del first[:]
+                     f(z.next())
+                 return value
+             items = list(tuple2)
+             items[1:1] = list(tuple1)
+             gen = imap(g, items)
+             z = izip(*[gen]*len(tuple1))
+             z.next()
+ 
+         def f(t):
+             global T
+             T = t
+             first[:] = list(T)
+ 
+         first = []
+         mutatingtuple((1,2,3), f, (4,5,6))
+         second = list(T)
+         self.assertEqual(first, second)
+ 
  
  libreftest = """ Doctest for examples in the library reference: libitertools.tex
***************
*** 560,564 ****
  
  def test_main(verbose=None):
!     test_classes = (TestBasicOps, TestVariousIteratorArgs, TestGC)
      test_support.run_unittest(*test_classes)
  
--- 590,595 ----
  
  def test_main(verbose=None):
!     test_classes = (TestBasicOps, TestVariousIteratorArgs, TestGC,
!                     RegressionTests)
      test_support.run_unittest(*test_classes)